Electronic systems composed of multiple devices housed in separate enclosures commonly require external signal interconnects between devices. These systems require that integrated EMC shielding be provided in the flexible cabling extending between enclosures. It is not unusual to find that the external connecting cables are among the largest structures in the system, with the result that common mode currents on these cables are almost always the source of an EMI (electromagnetic interference) problem. To control both differential mode and common mode signals it is necessary to provide both logic ground shielding about the signal lines and secondary frame ground shielding about the logic ground shielding.
High performance double shielded coaxial cables are a solution, but are too bulky and require large radius bends and as a result are not suitable for use in current state of the art devices that are continuously attempting to achieve smaller, more compact device sizes.